1. Microsatellite Mutations and Inferences About Human Demography
Microsatellites and their characteristics;
The application of microsatellites, including human demography inference.
BI820 3/23/04

2. Microsatellites and their characteristics
1. Microsatellites are tandemly repeated DNA motifs of 1–6 bp in length dispersed throughout
the whole genome;
(AT)5, (AT)6, (AT)3….
(ACT)1, (ACT)8, (ACT)3….
2. Microsatellites occur at a high frequency in all examined eukaryotes and at a lower frequency in
prokaryotic genomes;
3. Microsatellite loci increase and decrease in length due to polymerase slippage during DNA replication
and recombination, both of which are consequences of having a series of identical tandemly
repeated units.
4. Microsatellite loci are highly variable, even in organisms that display little genetic variation
5. Microsatellites are informative
6. Microsatellites are relatively straightforward to identify
(AT)5
(AT)7
(AT)10
PCR

3. X The applications of microsatellites
1. Originally used for family study;
2. Today applications include genetic mapping, forensics, studies of human genetic disease proliferation
and assessments of genetic diversity
3. Microsatellites are not preferred for genetic analysis;
Microsatellites have high mutation frequency, and have the ability to both gain or lose repeat unit.
---->The infinite site assumption is no long true for microsatellite analysis.
(AT)7 X
(AT)5-->(AT)7
(AT)8-->(AT)7
4. However, based on some statistical analysis of microsatellites, population expansion is still
observed in different subpopulations.